I am making some pretty good progress in terms of rigging the Creature. There are still quite a few things to do, but I find it helpful to make sure the mesh deforms correctly before finishing off the sculpt.

As of right now things are looking pretty good (but still basic). It was a pain to make sure that the Creature deformed nicely in both his land (walking) and water (swimming) postures. But the rig and mesh are very capable of doing both. So yay! :)